Figure 5.
Effect of TTA-P2 on NRT neurons. A, Same protocol as in Figure 1A was used to record the IT (●, top traces) and HVA Ca2+ currents (○, bottom traces) in an NRT neuron. TTA-P2 (1 μm) produced a 97% block of IT without a concomitant decrease in the amplitude of the HVA Ca2+ current. B, Continuous voltage record from an NRT neuron showing that 1 μm TTA-P2 induces a small hyperpolarization concomitantly with the block of the rebound LTCP evoked by an hyperpolarizing step (breaks in the trace) before (a) and after a 4 and 8 min wash-in (b, c) of the antagonist. C, D, Same protocols as in Figure 4, B and D, were used to study the effect of 1 μm TTA-P2 on NRT neuron excitability. C, The block of the rebound LTCP by TTA-P2. E, The graph presents the frequency–current plot from nine neurons. CTR, Control.